DIRS := $(foreach DIR,$(wildcard */),$(subst /,,$(DIR)))

.PHONY: default
default: make

.PHONY: $(DIRS)
$(DIRS):
	$(MAKE) -C "$@" $(ACTION)

.PHONY: clean
clean: ACTION=clean
clean: $(DIRS)

.PHONY: all
all: ACTION=all
all: $(DIRS)

.PHONY: make
make: ACTION=
make: $(DIRS)
